The overall objectives of the investigations begun in 1974 are to characterize in some detail, the mechanisms underlying the development of recurrent joint disease after immunization with live attenuated rubella virus vaccines. It is also hoped to learn whether natural or vaccine induced rubella virus infection contributes in any significant manner to the severity or the pathogenesis of juvenile rheumatoid arthritis. BIBLIOGRAPHIC REFERENCES: Chiba, Y., Sadeghi, E., Ogra, P.L., J. Immunol. 117:1684, 1976. Ogra, P.L., Chiba, Y., Beutner, K.R., Morag, A., Dev. Biol. Stand. 33:19, 1976.